During meetings, boards such as whiteboards, chalkboards, flipchart pads, and tackboards are commonly used to record information. In collaborative environments, several users may view, supplement and/or edit information recorded on the boards. In situations where the boards are passive, it is difficult and cumbersome to transfer information recorded on the boards to other media that facilitate storage and retrieval of the recorded information.
To deal with the above problem, automated capture systems to capture information recorded on a board have been considered. These automated capture systems include for example, automated copyboards, flipchart scanners, active or specialized pen systems based on acoustic time-of-flight, electromagnetic detection, or laser scanning as well as analog resistive whiteboards.( Although these automated capture systems have permitted information recorded on a board to be transferred to other media types, these automated capture systems suffer disadvantages.
In addition to the automated capture systems described above, camera-based systems to capture information recorded on a board have been considered. For example, U.S. Pat. No. 5,528,290 to Saund discloses a device for transcribing markings drawn on a whiteboard or blackboard into an electronic form using a camera-based board scanner. The scanner is in the form of a video camera mounted on a computer controlled pan/tilt head suspended from the ceiling or mounted to one side of the board. The camera is directed successively at small regions (tiles) of the board and snapshots of the tiles are captured until a complete image of the entire board is obtained. The camera image tiles slightly overlap with neighboring camera image tiles so that a complete image of the board is obtained with no missing spaces.
U.S. Pat. No. 5,581,637 to Cass et al discloses a device for transcribing markings drawn on a background surface such as a whiteboard or blackboard into an electronic form using a video camera. A registration light pattern is projected onto the background surface to be imaged. The projected pattern is selected to suit the properties of the video camera and the imaging environment. The video camera is directed successively at tiles of the background surface and snapshots of the tiles are captured until a complete image of the entire background surface is obtained. The pattern markings are processed using perspective transformations to determine the overlap properties of the camera image tiles and the distortion of each camera image tile. The resulting data is used to combine the camera image tiles to produce an undistorted image of the entire background surface.
U.S. Patent Application Publication No. US2004/0201698 to Keenan et al. discloses a camera-based system for capturing images of a background surface such as a whiteboard. The camera-based system includes a generally horizontal boom assembly mounted above the whiteboard that supports a plurality of cameras. The cameras look back at the whiteboard and are actuable to capture images of sections of the whiteboard. The camera images are stitched to form an entire image of the whiteboard.
In the above-described camera-based systems, it is typically desired that all information recorded on the background surface be captured in images acquired by the cameras. Unfortunately, in some instances images of the background surface are captured and processed when an obstacle such as a person, a piece of furniture or other object obscures a portion of the background surface from the fields of view of the cameras. The end result is incomplete images and wasted processing and memory resources. As will be appreciated, improvements in systems of this nature to obviate or mitigate the above disadvantage are desired.
It is therefore an object of the present invention to provide a novel system and method for capturing images of a target area on which information is recorded.